The Internal Revenue Service told Congress Friday it has lost a trove of emails to and from Lois Lerner, a central figure in the agency’s Tea Party controversy, sparking outrage from congressional investigators who have been probing the agency for more than a year.

The IRS said it cannot locate many of Lerner’s emails prior to 2011 because her computer crashed during the summer of that year.

Lerner headed the IRS division that processed applications for tax-exempt status. The IRS acknowledged last year that agents had improperly scrutinized applications for tax-exempt status by Tea Party and other conservative groups.

Republican congressional leaders were incensed.

“The fact that I am just learning about this, over a year into the investigation, is completely unacceptable and now calls into question the credibility of the IRS’s response to congressional inquiries,” said Rep. Dave Camp, R-Mich., chairman of the House Ways and Means Committee. “There needs to be an immediate investigation and forensic audit by Department of Justice as well as the inspector general.”

Sen. Orrin Hatch, R-Utah, said he was “greatly troubled” that the agency didn’t notify Congress when they first became aware of the computer problem.

“Today’s admission by the IRS that they cannot produce Lois Lerner’s emails is an outrageous impediment to our investigation,” Hatch said in a statement. “Even more egregious is the fact we are learning about this a full year after our initial request to provide the Committee with any and all documents relating to our investigation.”

Congressman Chaffetz reminds us that in past hearings, the IRS indicated that they DID have the emails but that it would possibly take ‘years’ to redact information from the emails before turning them over.